In an electric vehicle and a hybrid vehicle, there is used a battery module having a plurality of cell groups connected in series or in series-parallel, wherein the cell group has a plurality of secondary battery cells (electric cells) such as lithium electric cells connected in series or in series-parallel. Further, a device having a plurality of battery modules connected in series or in series-parallel is used together with a battery control circuit for controlling these battery modules as an electrical storage device.
In the case of connecting (live-line connection) the secondary battery cells connected in series and a control device for detecting the voltage of these batteries to each other, there is required a device for preventing a high voltage from being applied to an integrated circuit incorporated therein, namely a high current from flowing into the control device. In PTL 1, for example, there is used a special connector in which the lengths of the connector pins are changed so that the voltage detection lines are connected in ascending order of the battery voltage in a battery pack (assembly battery) having a plurality of secondary batteries connected in series-parallel when connecting the battery pack to the control device.
In PTL 2, there is disclosed a connector configured so that a high voltage is not applied to a cell controller IC (an integrated circuit) when performing the live-line connection for connecting the assembly battery and the cell controller IC to each other. The cell controller IC disclosed in PTL 2 is disposed for each of the cell groups each having a plurality of secondary battery cells connected in series to each other. The connector is configured so as to connect the GND line of the high potential side of the two cell controller ICs adjacent to each other and the VCC line of the low potential side thereof among a plurality of wiring lines for connecting the assembly battery and the cell controller ICs to the battery pack-side first and at the same time.